Your brain is like a muscle that grows and gets stronger when you stretch it. You wouldn’t run a marathon tomorrow without any training, right? If you’re serious about completing the marathon, you’ll start training and increase your distance incrementally.
Developing a rigorous course load throughout high school requires similar training. Colleges are not looking for perfection over four years—they are looking for growth. Each year’s curriculum should stretch your brain a bit further, but within reason, based on previous efforts. If you struggled for a C in a particular subject area, you might not be ready to jump to the honors level the next year. But if you earned an A or B without losing sleep, you might be ready for a more rigorous challenge. As rigor increases, it’s normal to experience a slight dip in your grades while your brain-muscle gets used to it. But over the course of the year, you’ll grow, and ideally be ready for more stretching the following year.